Metallic propeller and method of making



I 8, 1934. A. A HANDLER METALLIC PROPELLER AND METHOD.OF MAKING Filed Aug. 19,1929- s Sheets-Sheet 1 %3/ arm y A. A. HANDLER 1,957,499

METALLIC PROPELLER AND METHOD OF MAKING I Filed Aug. 19, 1929 s Sheets-Sheet 2 M I sailing ORNEY INVENTOR AZF/PED A. f/A/VDZEE y 855.1934? A. A. HANDLER 1,957,499

METALLIC PROPELLER AND METHOD OF MAKING Filed Aug. 19, 1929 3 Sheets-Sheet 3 RNEY Patented ay 8, 193 .4

UNIT

METALLIC PROPELLER, AND METHOD OF MAKING Alfred A. Handler, Cleveland, Ohio, assignor to Aluminum Company tion of Pennsylvania Application August 19,

35 Claims.

This invention relates to the art of propellers and is particularly associated with certain novel methods for manufacturing propeller products.

Present day manufacturing methods are lack- 5 ing in any processes for working individually the metal of the hub portion of a propeller. The known methods are also devoid of any steps for providing axial recesses in the propeller hub. A construction including a wrought hub perforated by an axialrecess is advantageous in aeronautical propellers as it lightens the article and yet leaves it with the properties of strength, toughness, etc. to the degree necessary to withstand severe service. Propellers made by conventional methods are characterized by a hub portion of metal which has not been worked as much as the metal of the blade portion. This is because the latter has been thinned out more than has the hub. In order for the metal of'the hub to exhibit the characteristics of hot wrought metal to theextent desired, it is essential that the original ingot, from which it is formed be reduced in cross-sectional area sufficiently to bring about the change in the characteristics of the metal. In the case of an aluminum base alloy a reduction of about 75% or more. is necessary for proper results. It is, therefore, necessary to start with an ingot having a comparatively large diameter in order to obtain this reduction in the hub.

In view of the foregoing this invention has as an object the broad proposition of providing methods for working the metal of the hub per-- tion of a propeller individually and which working is not necessarily accompanied by a working 5 of the blade portion. Such. a method has the advantage of permitting the manufacturing of the product to begin with an ingot of much smaller cross-sectional area than has formerly been the case, and yet provide a hub portion that is characteristically wrought. It further provides for the forming of the hub into a lightened construction such as by being recessed axially by the blade. Moreover, the individual working of the hub constitutes a method whereby the flow lines of the metal of the hub portion may be made to conform to the contour thereof.

This last mentioned feature provides for a greatly improved hub portion as the conformity of the flow lines to the contour renders the con:

struction more resistant to the stresses encountered in propeller use.

The individual metal working processes for the hub portion may take the form of metal upsetting, displacing or similar working operations.

Such methods serve to cause the metal to assume of America, a. corpora- 1929, Serial No. 387,016

the characteristics of wrought metal and also bring about a desired change in the shape of the hub portion. These operations are all closely related and simulate one another because the worked metal has substantially the same properties and qualities for propeller purposes.

More specifically, I propose to pierce the hub portion of a propeller while it is confined in dies of suitable shape. Such a piercing operation provides a recessed hub and is particularly adapted to the forming of a desired hub' structure, such as outstanding flanges.

This invention also involves the combination of metal working processes for the hub portion of a propeller with other propeller manufacturing steps. Itis my idea to provide a method including the individual working of the hub -and also rolling out processes, forging by dies, pressing, finishing and heat treating. v

More in detail, I intend to pierce the .hub portion of a blade in a series of steps in order'to upset or spread the metal thereof. This piercing ordinarily will follow the rolling and forging operations or it may be associatedwith pressing processes. These piercing operations involve the use of confining dies into which 'the metal is upset.

also pro-. 8'5 ave a prolonged period 1 egoing, other 'more'ide-i.

tailed objects and advantages will in part become apparent and in part be hereinafter stated as the description of the invention proceeds. For a full 'and more complete understanding thereof, refer ence may be had to the following description and accompanying drawings, wherein,

Figure 1 is a perspective view of a billet of metal before it is subjected to the processes of this invention. I

Figure 2 is a view similar to Figure 1 showing the billet as it is formed by the first rolling step.

Figure 3 is a plan illustration of a propeller after it has been roughly shaped by the rolling operations.

Figure 4 is a diagrammatic showing of the forging rolls.

Figure 5 is a sectional view through a part of the piercing apparatus.

Figure 6 is a showing similar to Figure 5 and develops a more advanced step in the upsetting process.

Figure 7 is a view similar to Figures 5 and 6 and brings out the final piercing operation.

Figures 8, 9 and 10 are sectional views taken about on the lines 8--8, 9-9 and 10--10 of Figures 5, 6 and 7, respectively.

Figure 11 is a plan view of a propeller after it has been shaped by the rolling out and upsetting processes, and,

Figures 12, 13, 14 and 15 are sectional views taken about on the lines 1212, 13-13, 14-14, 15-1 5 of Figure 11.

I wish to emphasize that my novel methods are designed to shape propeller blades from any of the metals or their alloys that have been found suitable for such use. In addition to an aluminum base alloy, which is taken for exemplary purposes as a preferred material to be fashioned into propeller shape, the following metals are mentioned among others as being susceptible to working by the method hereof: magnesium and the various magnesium base alloys, iron and steel, copper, and in its several combined forms, such as bronze and brass, and nickel in alloy com'positions such as Monel metal. I wish to note particularly that the magnesium base alloys are peculiarly adapted for the making of aeronautical propellers. Such alloys exhibit many of the properties of aluminum base alloys and are desirable for the same reasons as are the latter. An aluminum base alloy which has been found suitable for aeronautical propeller use is one containing approximately ninety-four .percent aluminum, four and five-tenths percent copper, seventy-five hundredths percent manganese, and seventy-five hundredths percent silicon.

A propeller blade such as made by the instant methods is described as being designed for use in gaseous fluids. This because blades for aircraft purposes must have all of the properties of strength, toughness and the like, to the highest degree necessary and still be as light as is feasible. These conditions are, to a certain extent, peculiar to aircraft and the improved methods are herein set forth as applied to aeronautical propeller manufacture. It is obvious, however, that the invention would be employed in the making of propellers thatoperate in other fluids, such as water.

In the present embodiment the propeller is made from an aluminum base alloy of the composition hereinbefore set out.

Referring now to the drawings, a metal billet that indicates the starting point of my method is shown in Figure 1 and designated A. The true starting point of' the method is a cast ingot. Whether or not this has been worked down to the form of a billet as shown or remains in ingot form is immaterial to this invention. The method must begin somewhere with a casting and any methods starting out from a worked billet merely presume the prior working of the ingot into the billet form. The exact metal working operations which are availed of to reduce the ingot to billet form 'are not essential to this invention. A preferred method might include rolling out processes for this step which may be carried out in a blooming mill. This billet A is formed with a handle portion or tong hold 1 in any preferred manner. This portion 1 constitutes a means which is gripped by a pair of tongs or like tool to handle the billet during the operations to be hereinafter described.

The billet A is first heated to a condition wherein it is easily workable, for instance, to a temperatureof about eight hundred twenty degrees F. It is then subjected to the action of forging rolls voids, dross, impurities and the like.

indicated diagrammatically in Figure 4 as R. The rolling out operations preferably comprise a series of rolling steps or passes through the rolls R, which gradually work the billet A into the form shown in Figure 3 and impart to it the approximate sectional arc of a finished propeller. At this point the billet has taken on the general shape of a propeller and for the purposes of this description is referred to as B. The showing of Figure 2 develops the billet A after it has been deformed by the first rolling out step.

The rolling out operations provide, in somewhat rough form the blade B having a hub portion H. The metal in the blade portion will have been worked sufficiently to effect a reduction in its cross-sectional area of about seventy-five percent or more. If the reduction has not been carried out to this extent in the blade portion by the rolling out steps it will be completely effected by the subsequent forging or pressing operations,-

or both. However, the latter do not materially affect the hub portion H, so if the metal thereof has not been reduced to the critical point of about seventy-five percent reduction by the rolling out processes this will be attained by the subsequent hub working operations.

The rolling out steps impart to the metal a fine grained structure which is characterized'by flow lines that conform in direction to the contour of the blade. A flow line in a wrought metal bears a certain relation to fiber in wood and the term fiber has come into quite common usage in the wrought metal field. It has been defined as a condition ofparallelism of lines or structural details and may frequently be found in any wrought metal. show itself through undissolved constituents, segregations, or non-metallic inclusions. Grains may quite often be found to be elongated in the direction of the fiber and the fiber will parallel the direction of the previous working.

Fiber or flow lines as I term them, may sometimes be visible to the unaided eye when a specimenv of wrought metal is deeply etched, or may be apparent only on microscopic examination. Going even further, certain types of flow lines caused by preferred orientations of crystal axes are only distinguishable by X-ray analyses.

Intimately associated with the flow line arrangement as a part thereof is any laminated structure which may be caused by the presence of Such laminations will be elongated lengthwise of the blade by the rolling and will assume the directions of the flow lines. Moreover, the size of the grains varies in a uniformly progressive manner with the thickness of the blade and the working received by the metal. Concentration or localization of voids, impurities, etc. in transverse relation to the propeller is also prevented by the rolling out. Such concentration of the voids ordinarily would result in a blistering or surface cracking of the metal. These features clearly On visual examination it may demonstrate the desirability of the rolling out tions substituted therefor.

ever, that a complete manufacturing method maypressing dies.

ultimate vThe die 6 and piercing tool '7 are shape shown by the rolling operations and the forging by dies only aifects it slightly. The forging operations of steps which gradually form the blade into what is practically its finished shape.

If desired, the shaping by forging may be dis pensed with wholly or in part and pressing opera-.

include both of these processes. As in the case of forging, the blade is first heated to a point where it is workable and it is then subjected to the The action of the latter is characterized by the prolonged or continued application of the deforming force. This metal working action simulates the rolling out steps in this respect and also the upsetting operations, to be later described.

The metal working operations for further shaping the propeller after it has been rolled out are, for the purposes of this description, classified generally as forging. This term is intended to include all the metal working methods which function to form, shape, or work the metal by applying a deforming force thereto. Such methods may comprise forging by dies and pressing as above noted.

Subsequent to the forming of the blade portion by rolling and forging, or pressing, or both, which operations have shaped the hub portion I-I into a somewhat cylindrical shape, the handle portion or tong hold 1 is removed in any convenient manher as by cutting. The hub portion is then deformed, preferably by a series of piercing operations which upset the metal of the hub portion. It is to be clearly understood that I am not to be confined to the exact upsetting operations dis closed because obviously equivalent processes could be availed of to attain the same ends.

In order to render the metal of the hub more easily workable, it is preferably heated to a proper point. The hub end of the blade is then introduced to the split die 2 shown in Figure 5 which closes and grips the hub. The latter is formed with grooves and ribs 3 which define the shape 'of certain hub structure in the form of ridges and grooves which are to be present in the product. When the blade is first positioned in the die 2 .the metal of the hub portion occupies the position indicated by the dotted lines in Figure 5.

A piercing tool 4 having a point 5 is now operated by proper force and pierces the hub portion of the blade axially. This piercing of the blade upsets the metal thereof so that it completely fills the space between the die 2 and piercing tool 4.

The blade is now' removed from the die 2 and introduced into the die 6. Theaction of the die 2 and piercing tool t has been to deform the metal of the hub to a shape resembling designed to still further carry out this deformation. When first positioned in the die 6 the hub H assumes the dotted line position. The tool '7 is then operated so that its point 8 pierces the hub by first entering the opening formed by the point 5. The metal is upset by this operation and displaced into the grooves 9 formed in the die 6. The hub portion of the blade will now have more nearly reached its ultimate formation;

While two or even one piercing operation may be found to be suificient to properly form the hub of the finished blade, I propose to avail of three of these operations. It is evident that the uppreferably comprise a series My thought is, howits final form.

setting may be broken up into as many operations as found desirable under any particular circumstances.

After the tool 7 has been cleared away from the blade it is removed from the die 6 and introduced into the final die. Grooves l1 and rib 12 in the latter define the final hub structure. A piercing tool 13 having a point 14 is operated in the usual manner as above described and the metal of the hub H is upset from the dotted line position into the space between the die 10 and tool 13. g

It is notable that the exact metal flowing action imparted to the metal of the blades by piercing is dependent on the size and shape of the piercing tool and confining die. Under proper dimensioning of these parts the metal will be both upset and caused to fiow axially by this piercing. Such 1 While the point 5 is of 'a substantially round shape, the point 8 is flattened out somewhat and the point 14 even more so. These points provide the openings 15, 16 and 17 shown in Figures 8, 9 and 10, respectively, during the several piercing steps.

After the hub portion has been finally shaped, the blade is subjected to the usual finishing operations, comprising cleaning, sizing, trimming and heat treating, and final finishing which may in clude polishing and trimming.

The upsetting or flowing of the metal of course changes any cast characteristics remaining inherent thereto after rolling to those of hot wrought metal. The final product is remarkably free from any irregular grain structure and coarse grains, and it is notable that the grains assume flow lines conforming in direction with the contour of the propeller. Furthermore, it is characteristically wrought throughout and the hub portion is very light and yet of sufficient strength to meet the service conditions it will be subjected to. 120

What I claim is:' i

1. In propeller manufacture. the method of shaping the hub of a propeller and root general blade shape, and then working the hub 13% portion and root portion of the blade into finished form by axially piercing the metal thereof.

3. The method of making a propeller blade which consists of working a piece of metal into rough propeller shape. forming the hub portion of the blade with a hollow, and carrying out the said working and forming operations to create a flow line arrangement in the grain structure of the hub portion of the blade'conforming with the longitudinal contours of the propeller.

4. In propeller manufacture, the method of working a piece of metal down to a rough blade shape, having blade and hub portions, and carrying out the working to provide a longiudinal recess extending through the hub portion into the blade portion and at the same time creating a grain structure in which the grains vary in size uniformly throughout the said blade and hub portions.

5. In the making of metallic propellers, the

method which consists in applying a. deforming force to a piece of metal to cause the latter to roughly assume the shape of a propeller blade having a hub portion, prolonging the time of application of the force to thoroughly work the crystals of the metal, and then working the hub portion by upsetting the metal thereof.

6. In the making of metal propellers, the method which consists in deforming a piece of metal into rough blade shape with the grain structure of the metal having flow lines conforming in direction to the contour of the blade, the blade being formed with a hub portion, and then deforming the latter to provide a hollow therein and working the metal thereof to a condition wherein the flow lines conform to the contour of the hub portion.

7. In propeller manufacture, the method which comprises forming a piece of metal into the general shape of a propeller blade, having hub and blade portions, further shaping the blade portion by forging, and then upsetting the hub portion into its final shape.

8. In propeller manufacture, the method which comprises forming a piece of metal into the general shape of a propeller blade, having hub and blade portions, further shaping the hub and blade portions by forging and pressing processes and then deforming the metal of the hub portion by upsetting operations.

9. In propeller manufacture, the method which comprises forming a piece of metal into the general shape of a propeller blade, having hub and blade portions, continuing the shaping of he blade by pressing processes, and then finally forming the hub portion by a piercing operation.

10. In the making of metal propellers, the method which consists of rolling a billet of metal out into the rough shape of a propeller blade, having a hub portion, further shaping the blade by forging, and then axially piercing the end of the hub portion of the blade to spread the metal thereof and provide a hollow hub portion.

11. In the making of metal propellers, the method which consists of rolling a billet'of metal out into the rough shape of a propeller blade, further shaping the blade by forging, and then operating on the hub portion of the blade with a series of piercing operations, which gradually work the metal of the hub into its ultimate form.

12. In the making of metal propellers, the method which consists of rolling a billet of metal having the characteristics of cast metal out into the rough shape of a propeller blade, further shaping the blade by forging, and then working the hub portion of the blade to effect a reduction of the metal sufiicient to change the characteristics thereof from those of cast metal to those of wrought metal.

13. In the making of metal propellers, the method which consists of rolling a billet of metal having the characteristics of cast metal out into the rough shape of a propeller blade, further shaping the blade by forging, and then further working the metal of the hub portion to effect approximately a seventy-five percent reduction in the cross-sectional area of the hub portion.

14. The method of making a propeller blade which consists in heating a billet of an aluminum base alloy and working the billet while heated into a blade shape having hub and blade portions, and then forming the hub portion into a shape having a recess extending lengthwise of the propeller.

15. The method of shaping the hub portion of a metal propeller which consists in first forming a round hole in the hub portion, and then elongating the hole and forming the elongated portion of the hole in a flattened out shape.

16. The method of forming the hub portion of a propeller and root portion of the blade which comprises piercing themetal of the hub and blade axially to provide an opening therein, and then performing further piercing operations to change the shape of the hub portion, and to lengthen the opening therein.

17. In propeller manufacture, the method which consists in rolling out an aluminum base alloy billet to provide hub and blade portions and then working the said portions by a series of piercing operations to form a flattened out recess in the blade portion.

18. In the making of metal propellers, the method which lies in deforming a piece of metal into the rough shape of a blade having a hub portion, and then upsetting the metal of the hub portion by a series of piercing operations to provide a recess therein and also an outwardly extending flange.

19. In propeller manufacture, the method which comprises working a piece of metal while heated into the general shape of a blade having a hub portion, further shaping the blade by forging, and then gradually working the hub portion into its ultimate shape by a series of upsetting operations.

20. In propeller manufacture, the method which comprises working a piece of metal while heated into the general shape of a blade having a hub portion, further shaping the blade by forging, while the metal is in a heatedcondition, and then performing a series of piercing operations axially on the hub portion to provide a recess therein.

21. In the making of metallic propellers, the method which comprises rolling out an aluminum base alloy billet while in a heated condition to provide a blade in rough shape, having a hub portion, further shaping the blade by forging, and 120 then axially piercing the metal of the hub portion.

22.'In the making of metallic propellers, the method which comprises rolling out an aluminum base alloy billet while in a heated condition to provide a blade in rough shape, having hub and blade portions, further shaping the blade by performing forging and pressing operations while the blade is in a heated condition, and upsetting the metal of the hub and blade portion by a lon gitudinal piercing operation.

23. In propeller manufacture, the method of making a metal blade which consists of rolling out a metal billet while in a'heated condition, forging the rolled out metal into a blade shape having a cylindrical hub co-axial with the blade, and then forming an axialrecess in the hub.

24. In propeller manufacture, the method of making a metai blade which consists of rolling out a metal billet while in a heated condition, forging the rolled out metal into a blade shape having a cylindrical hub, and then upsetting the metal-of the hub into a shape characterized by a flattened recess extending axially of the blade.

25. In propeller manufacture, the method of making a metal blade which consists of rolling out a metal billet while in a heated condition, forging the rolled out metal into a blade shape having a cylindriral hub, piercing the metal of the hub by a series of piercing operations to pro- 159 vide an outwardly extending flange thereon, and then carrying out finishing operations to provide the final product.

26. The method of making a propeller blade which consists in heating a metal billet to a workable conditionfrolling out the metal while heated, forging the metal into propeller shape while in a heated condition, and which shape is formed with a hub portion, and then piercing-the hub to provide a recess extending axially of the blade.

27. The method of making a propeller blade which consists in heating a metal billet to a workable condition, rolling out the metal while heated, forging the metal into propeller shape while in a heated condition, and which shape is formed with a hub portion, and then gradually deforming the metal of the hub to provide a recess extending axially of the blade and an outwardly extending flange.

28. The method of making a propeller blade which consists in heating a metal casting to a workable condition, rolling out the metal while heated, forging the metal into propeller shape while in a heated condition, and which shape is formed with a hub portion, confining the hub portion in a die, and then piercing the hub axially of the blade with a piercing tool to upset the metal to fill the die. I

29. The method. of making a propeller blade which consists in heatinga metal casting toa workable condition, rolling out the metal while heated,forging the metal into propeller shape while in a heated condition, and which shape isformed with a hub portion, confining the hub portion in a die, and then piercing the hub with a piercing tool to upset the metal into the die, and repeating said confining and piercing operations with differently sized dies and piercing tools to graduaL y change the shape of the hub portion into its final form.

30. In propeller nfnufacture, the method of heating a billet of an aluminum base alloy, rolling out the block while heated by a series of roll-' ing operations, which gradually develop the blade in its rough shape, reheating the blade, forging the reheated blade ,to provide a substantially finished blade portion and a hub portion, and then deforming the hub portion by piercing operations which upset the metal into ahub form having a flattened recess extending the blade.

I 31. The method of making a propeller from an aluminum base alloy comprising sizing,

ing polishing.

a series of forging axially of which consists in working an ingot of the alloy into billet form, rolling out the billet while he ted into the general shape of a prope er, furth r shaping the propeller by forging hile heated, working the hub portion into its ultimate form by piercing operations, finishing by operations including cleaning, sizing and trimming, and then heat treating the shaped propeller.

32. Themethod of making a propeller from an aluminum base alloy which consists in rolling an ingot of the alloy into billet form,.heating the billet to a workable condition, gradually working the billet while heated into the general shape of a propeller by a series of rolling out operations, further shaping the partially shaped article by forging operations carried out while the metal is rendered workable by heating, finishing by steps cleaning and trimming, heat treating, and finally finishing by methods includ- 33. The method of making a propeller from an aluminum base alloy which consistsin rolling an ingot of the alloy into billet form, heating the billet to a workable condition, gradually working the billet while heated into the general shape of apropeller by a series of rolling out operations, further shaping steps including sizing and trimming.

34, In the manufacture of propellers, the process which consists of forming a substantially cylindrical billet of a cross sectional size providing suflicient metal to carry the forces to which a finished propeller blade is subjected at or near the root portion of the blade, working one end and the major portion of the billet into blade shape and up etting the opposite end of the billet to form a homogeneous enlargement thereof of greater diameter than the initial diameter of the billet and to work said last mentioned end of the billet to improve the properties thereof.

the partially shaped article by operations, and finishing by 35. In the manufacture of propellers, the proc- Y ess which consists of forming a substantially cylindrical billet of a cross sectional size providing sufiicient metal to carry the forces to which a finished propeller blade is subjected-at or near the root portion of the blade, working one end and the major portion'of" the billet into blade shape and'radially spreading the opposite end of the billet by an upsetting operation to form an enlargement thereon of greater external diameter than the initial diameter of the billet and to improve the properties of said end of the billet.

, ALFRED A. HANDLER. 

